摘要
      介绍奇异变形杆菌是肠杆菌科的一部分，对各种抗菌药物具有天然耐药性。近年来，由耐碳青霉烯的奇异假单胞菌（CR-PMI）引起的严重医院感染的爆发频繁报道。在中国和其他地方，很少有关于这种细菌的全基因组分子特征的研究，这刺激了这项研究的实施。
假设CR-PMI菌株含有多种耐药基因，对常用抗菌药物具有较高的耐药率。
目标我们的目的是确定CR-PMI菌株的耐药性机制和同源性，并为临床治疗和控制医院感染提供理论依据。
方法论使用基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF-MS）进行细菌种类鉴定。使用VITEK 2系统和Kirby Bauer（K-B）圆盘扩散法测定抗菌药物敏感性。全基因组测序（WGS）由Illumina平台NovaSeq测序仪进行。抗生素耐药性基因（ARGs）是使用Abritate的NCBI数据库进行鉴定的。质粒复制子类型使用基因组流行病学中心提供的PlasmidFinder进行鉴定。
后果2019年7月至2021年9月在我院收集的5株CR-PMI菌株对除氨曲南（ATM）、阿米卡星（AMK）和头孢替坦（CTT）外的几乎所有抗菌药物都有耐药性。所有CR-PMI菌株均含有碳青霉烯类耐药基因新德里金属-β-内酰胺酶1（blaNDM-1），两株菌株含有超广谱β-内酶（ESBL）基因blaPER-4和blaCTX-M-65。5株CR-PMI菌株分别含有27、18、30、25和24个耐药基因。大多数抗微生物耐药性基因是氨基糖苷类（n=14），其次是头孢菌素类（n=7）。系统发育树分为五个进化群，五个CR-PMI菌株属于四个进化群B–E。
结论CR-PMI菌株对常用抗菌药物的耐药率较高，且含有碳青霉烯类耐药基因blaNDM-1。CR-PMI菌株在不同的病房、不同的时间表现出多克隆的趋势。最重要的是，所有被鉴定的菌株都含有重要的抗微生物耐药性基因，这可能导致严重的耐药性传播和致命的多重耐药细菌感染。
ABSTRACT
 
Introduction. Proteus mirabilis is part of the family Enterobacteriaceae, and is naturally resistant to various antimicrobial drugs. In recent years, outbreaks of severe nosocomial infections caused by carbapenem-resistant P. mirabilis (CR-PMI) have been frequently reported. Few studies exist on the whole-genome molecular characteristics of this bacterium in China and elsewhere, which stimulated the implementation of this study.

Hypothesis. CR-PMI strains contained the multiple drug resistance genes and exhibited a high resistance rate to commonly used antimicrobial drugs.

Aim. Our goals here were to identify resistance mechanisms and homology of CR-PMI strains and provide a theoretical basis for clinical treatment and controlling nosocomial infections.

Methodology. Bacterial species identification was carried out using matrix-assisted laser desorption/ionization time of flight MS (MALDI-TOF-MS). Antimicrobial susceptibility was determined using the VITEK 2 system and Kirby-Bauer (K-B) disc-diffusion method. Whole-genome sequencing (WGS) was conducted by the Illumina platform NovaSeq sequencer. Antibiotic resistance genes (ARGs) were identified using the NCBI database with Abricate. Plasmid replicon types were identified using PlasmidFinder, available at the Center for Genomic Epidemiology.

Results. Five CR-PMI strains collected in our hospital from July 2019 to September 2021 were resistant to almost all antimicrobial agents except aztreonam (ATM), amikacin (AMK) and cefotetan (CTT). All CR-PMI strains contained the carbapenem resistance gene New Delhi metallo-β-lactamase 1 (blaNDM-1), and two strains harboured extended-spectrum β-lactamase (ESBL) genes blaPER-4 and blaCTX-M-65. The five CR-PMI strains contained 27, 18, 30, 25 and 24 drug-resistance genes, respectively. Most antimicrobial resistance genes were detected for aminoglycosides (n=14), followed by cephalosporins (n=7). The phylogenetic tree was divided into five evolutionary groups, and the five CR-PMI strains were in the four evolutionary groups B–E.

Conclusion Overall, CR-PMI strains exhibited a high resistance rate to commonly used antimicrobial drugs, and contained the carbapenem resistance gene blaNDM-1. The CR-PMI strains showed a polyclonal trend in different wards at different times. Most importantly, all strains identified contained important antimicrobial resistance genes, which may lead to severe drug resistance transmission and fatal multiple resistant bacterial infections.

https://www.microbiologyresearch.org/content/journal/jmm/10.1099/jmm.0.001648